Piston



G. M. SCOTT June 17, 1930.

PISTON 5 Sheets-Sheet 1 Original Filed Aug. 14. 1l928 A tiorney June 17, 1930. 'GI M. scoTT PISTON 5 Sheets-Sheet 2 Original Filed Aug. 14. 1928 Inventor Q' JW# June 17, 1930. G. M. scoTn' 1,765,103

PISTON Original Fled Aug. 14. 1928 5 Sheets-Sheet 5 lllll Inventor gw. JCU# -Other objects and advantages ot the inec l.

Patented .inne 17, i939' j :un

ommenv iut.y sooTT, or TULSA, OKLAHOMA PISTON n 1929. Serial o This is la divisional application of the application for'patent filed by me August 14, `1928, Serial No. 299,474. `r fl The present .invention relates toa piston construction embodying self ycooling features.

One of the important'objects-,ofthe present invention is to provide an improved piston construction adapted. particularly for use in connectionwith air compressors wherel 10 intheparts of the piston can be readily and .easily assembled or disassembled, without necessitating the entire dismantling of the fair compressor, thus saving considerable time ,and labor. v

vention will become apparent duringthfe Acourse of the following detailed description, taken in connection with the laccompanying v drawings, wherein: 1 Figure f1 isr ay vertical sectional-view through anair compressor illustrating the adaptation' of my invention with respect thereto.: l

Figure y2 is asectional view, taken approxl imatelyV 'on' the line22 of Figure 1 and looking yin the direction .of the arrows. n Figure 3l is a sectional view, ltaken along the line 3-3 of Figure 2, and( f Figure ,4 is an enlargedy sectional view through the piston andy the adjacent portion yof the cylinder showing the manner in which Vthe parts ofthe piston are assembled. 'l In the drawings, wherein Viiorithevpurpose of illustration is shown the .preferredv embodimentv of my invention, the numeral'l designates rgenerally they supporting'. ybase uponwhichvanair compressor structure is mounted, saidcompressor, in the present inrstance,rcomprising a pairof spaced channel rails2.V "A base plate 3 is ysecured across the top of' these spaced channelrails'by any appropriate fastening means such as is shown at-4, `with reference more particularly to Figure 2 of the drawings. y v

Thevertically disposed cylinder 5 has its lowerend open and resting on the upper tace of the central base'plate 3, thek outer face of *the cylinder being provided with spaced coolingy fins 6, substantially throughout its length.` An elongated cylindrical casing 7 f eating movement withinthe casing.y `@per- 13 and 4`of the drawings.

eter oi the cylindrical body 38 andthe shoulder 42 is formed atthe junction of the threads y Original application filed August 14, 1928, Serialy No. 299,474. i Divided` and this application led July 25,

Vhas its lowerA end encircling the upper portion .of the cylinder 5 and the` lower end of this VVcasing. rests fin an angular' groove 8y formed in the uppervface oi an annular col- .A lar or shoulder formed on the upper portion of the cylinder 5,-v as clearly illustrated in Figures land 2.

Upon the upper end ci the casing is mounted a circular chamber l5; within one wall oi which is ournaled a shaft 19 havinga pulley wheel orother drive connection 26y mounted on lits outer end and'witli an eccentric 28 carriedy at its inner end, and to which a piston rod 14 .isoperatively attached for recipro-y able withinthe cylinder 5 is afpiston. 37 i which includes a cylindrical body 33, that is open at its upperend to provide anair inlet. The lower portion of the body 38 terminates .-1 in the reduced'externally threaded head 39 that is formed with a series of spacedair emitting openings 40ithat are arranged concentrically with respect to the enlarged central opening 41, as clearly shown in LFigures rDetachably secured on the reduced externally threaded head 39 of the body 38, is the externally threaded cap 42 whose diameter is substantially the same as the louter diamso of the cap with the remaining `portion of the .peripheral portion of the said cap whereby to provide a cooling chamber 43 between the perforated head 39 andthe capv 41, as illus- Y trated inFigure 4. f 'Y y AvThe Vperipheralwall of the cap` r41 is formed' in its outer ytace witha ring receiving groove, within which piston rings 44 are tted. The cylindrical body 38 oi the piston 7 is` provided with an additional piston ring 45 at the intermediate .portion thereof for engagement with the inner face voi thesleeve or lining 36, provided for the cylinder 5. The body oi the piston ris furthermore formed with the usual bosses 46 for receiving the pin 47 and a'lock screw or other appropriate element 28 is rthreaded* through n one oithese bosses ior'engagement with the m wrist pin, whereby to secure the same in position.

The lower end of the connecting rod 14 is detachably associated with a wrist pin encircling unit designated generally at 49 and which includes a circular head 29 formed with a threaded socket 30, for receiving the Yend of the connecting rod. A ball bearing assembly 32 is interposedV between Vthe circu-A lar head 49 and the wrist pin to provide an anti-friction connection between such parts.

The lower end of the connecting rodis provided with a lubricating receiving cavity 51 which is filled up through a suitable opene ing formed in thev side thereof and which opening is normally closed by means of the plug 52. Communication'betwee'n this cavity 51 and the ball bearing assembly 1s afforded through the medium of the passage 53, whereby the lubricant may be supplied to the ball bearing. Y Y

The cap 4l is formed with an enlarged central threaded opening into which a ring like member 54` is'detachably secured, which ring like member has-its bottom ,inner edge bevelled to provide a valve seat 55. A valve stem guide 56 is arrangedcentrally of the ring 54 and is supported at its lower end on the ring, in any appropriate manner. The upper end of this guide extends inwardly through the central opening 41 formed inthe perforated head 39, as clearly illustrated in Figure 4 of the drawings.'

A valve stem 57 is slidably disposed through the Yvertical tubular guide 56 and carried by the lower endof this valve stem is a valve 58 that cooperates with the valve seat 55. A spring retaining member 59 is securedy on the upper threaded end of the valve stem 57 for disposition Within the reduced 'rib 39 of the cylindrical body 38, and an expansible coil spring 60 encircles the tubular guide 56, and is disposed between the retaining member 59 and the support for the guide for normally urging the valve stem upwardly to maintain the valve 58 in closed position against the valve seat as shown in Figure 4. c Y

VThe end of the cylinder 5 is provided with a compression chamber 61. The base plate 3 that-provides a closure for the open lower end ofthe'cylinder 5 is formed with a cavity 62 at the juncture of the lower end of the' cylinder with the base plate and this detail is more clearly Vdisclosed in Figures 1 and 2 of the drawings. The central portion of the base plate is further formed with an enlarged Vcentral opening into which substantially the upperportion of an outlet valve cage 63 and this cage is secured in a rigid manner by a clamping ,ring 64, that engages with an annular `fiange 65, formed on the outer wall of the valve cage 63. A suitable post or the like, shown at 66, is disposed through spaced openings formed in the clamping base `end ofk which is formed or otherwise secured the valve 68. This coil spring engages at its lower end with the guide 71 arranged in the cage forthe valve. -The lower open end of the cage 63 has threaded therein the upper end of an elbow 7 2 and connected with the other endof this elbow is the compressed air dischargepipe 73, extending through an opening 74, 'formed in the base portion of either or both of the channelledV base plate supporting rails 2,'as shown in Figure 2. i s Y It will be apparent thatV duringthe up'- Ward movement of thev piston 37 inthercyl- 1 nder 5, air entering the lcylinder at the upper end thereof yis forced downwardly "through the opening 40 and will enter thev cooling chamber 43 through the openings 40, from which chamber it is forced out into the compression chamber 61 when the Vvalve 8 is screwed into an open position bythe inrlklsh-V ing air.l Therush ofair passing through the restricted openings 40 Ywill serveto cool the air and on the down stroke ofthe piston in the cylinder, the. air trapped in the chamber 43 will act as a cooling medium for the piston, while the air in the chamber'l will be compressed and will be forced out through the valve cage 63,when the valve 6,8 is moved to an open positionby the Vairunder pressure and the compressed airjwill be` discharged out through the pipe 73; v Y

It is obviousas set forth in the specifica tion that various changes maybe resorted to without departing from the spiritof the invention or they scope ofthe appended claims.

What is claimed is: r

1. In a piston construction, a cylindrical body open at one end to provide va fluid inlet,

the closed end of the cylindrical body being ing chamber.l

2. In a piston construction, a cylindrical body open at one end to provide afluid inlet, the other end of said body being reduced to provide a head, said head beingV provided with a plurality of fluid discharge openings, a cap detachably secured at the reducedhead .portion and spaced therefrom toV provide a cooling chamber to receive the uid discharged through said openings, and a spring pressed outlet valve carried b said cap to permit the discharge of fluid romr the Vcooling chamber.

In testimony whereof I ax my signature.

GEORGE M. Sco'r'r. 

